Therapeutic compounds

ABSTRACT

The invention provides compounds of Formula (I):
 
R 1 ≡R 2   (I)
 
wherein R 1  and R 2  have any of the values or specific values defined herein, as well as compositions comprising such compounds and therapeutic methods comprising the administration of such compounds.

PRIORITY OF INVENTION

This application is a continuation of U.S. patent application Ser. No. 12/027,154 filed on 6 Feb. 2008, which issued on 26 Jun. 2012 as U.S. Pat. No. 8,207,381 and claims priority under 35 U.S.C. 119(e) from U.S. Provisional Application No. 60/899,788, filed 6 Feb. 2007. The contents of these prior applications are hereby incorporated by reference, in their entireties.

GOVERNMENT FUNDING

The invention described herein was made with government support under Grant Number CHE-0213502 awarded by the National Science Foundation. The United States Government has certain rights in the invention.

BACKGROUND OF THE INVENTION

Chemotherapy plays a major role in the management of cancer (e.g., breast cancer). For individuals with recurrent or metastatic disease, systemic chemotherapy is often the treatment of choice. Unfortunately, systemic chemotherapy is rarely curative. In addition, treatment with standard chemotherapy agents, such as cyclophosphamide, 5-FU, doxorubicin and paclitaxel, results in significant side effects and is rarely curative in cases of advanced disease. Consequently, breast cancer alone claims the lives of close to 41,000 women each year in the U.S. Therefore, there is a pressing need for new anticancer agents with unique activity and/or fewer side effects.

SUMMARY OF THE INVENTION

Certain embodiments of the present invention provide compounds that have anti-cancer activity. Accordingly in one embodiment the invention provides a compound Formula (I): R₁≡R₂  (I) wherein:

-   -   R₁ is carboxy, (C₁-C₂₀)alkoxycarbonyl,         (C₂-C₂₀)alkenyloxycarbonyl, (C₂-C₂₀)alkynyloxycarbonyl,         (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which         (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, is         substituted with one or more groups independently selected from         halo, hydroxy, mercapto, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy,         (C₂-C₂₀)alkynyloxy, aryloxy, heteroaryloxy,         (C₃-C₂₀)cycloalkyloxy, heterocyclyloxy, (C₁-C₂₀)alkylthio,         (C₂-C₂₀)alkenylthio, (C₂-C₂₀)alkynylthio, carboxy,         (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl,         (C₂-C₂₀)alkynyloxycarbonyl, aryl, heteroaryl, cycloalkyl,         heterocyclyl, NR_(a)R_(b), (C₂-C₂₀)alkynoyloxy, and         arylcarbonyloxy;     -   R₂ is CF₂Br, CFHBr, CF₂Cl, CFHCl, CFBr₂, CFCl₂, CBr₃,         C(R_(c))(R_(d))Br, C(R_(c))(R_(d))Cl, CF(R_(e))Br, CF₂I, CFHI,         C(R_(c))(R_(d))I, CF(R_(e))I or CCl₃;     -   each R_(a) and R_(b) is independently H, (C₁-C₂₀)alkyl,         (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl,         (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy,         (C₂-C₂₀)alkynyloxy, or aryl-(C₁-C₂₀)alkoxycarbonyl;     -   each R_(c) and R_(d) is independently H, (C₁-C₂₀)alkyl,         (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl,         (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, or         (C₂-C₂₀)alkynyloxy; and     -   R_(e) is (C₁-C₂₀)alkyl, (C₁-C₂₀)alkanoyl,         (C₂-C₂₀)alkenylcarbonyl, (C₂-C₂₀)alkynylcarbonyl,         (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, or (C₂-C₂₀)alkynyloxy;     -   wherein each aryl, heteroaryl, heterocyclyl, aryloxy,         heteroaryloxy, arylcarbonyloxy or heteroarylcarbonyloxy of R₁ is         optionally substituted with one or more groups independently         selected from halo, hydroxy, nitro, cyano, trifluoromethyl,         trifluoromethoxy, mercapto, carboxy, (C₁-C₂₀)alkyl,         (C₂-C₂₀)alkenyl, (C₂-C₂₀)alkynyl, (C₁-C₂₀)alkoxy,         (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, (C₁-C₂₀)alkylthio,         (C₂-C₂₀)alkenylthio, (C₂-C₂₀)alkynylthio,         (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl,         (C₂-C₂₀)alkynyloxycarbonyl, aryl, heteroaryl, aryl(C₁-C₂₀)alkyl,         heteroaryl(C₁-C₂₀)alkyl, aryl(C₂-C₂₀)alkenyl,         aryl(C₂-C₂₀)alkynyl, heteroaryl(C₂-C₂₀)alkenyl,         heteroaryl(C₂-C₂₀)alkynyl, (C₁-C₂₀)alkanoyloxy,         (C₂-C₂₀)alkenoyloxy, (C₂-C₂₀)alkynoyloxy;     -   or a salt thereof.

In one embodiment of the invention the compound of Formula (I) is not 4-bromo-4,4-difluorobut-2-ynoic acid.

In one embodiment of the invention the compound of Formula (I) is not 6-bromo-6,6-difluoro-2-methylhex-4-yn-3-ol.

In one embodiment of the invention the compound of Formula (I) is not 1-bromo-1,1-difluoro-non-2-yn-4-ol.

The invention also provides a pharmaceutical composition comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

The invention also provides a method for treating cancer in an animal comprising administering a compound of Formula (I) or a pharmaceutically acceptable salt thereof to the animal.

The invention also provides a method for treating a pathological condition or symptom in an animal wherein the activity of DNA methyltransferase 1 is implicated and inhibition of its action is desired comprising administering a compound of Formula (I) or a pharmaceutically acceptable salt thereof to the animal. Such conditions include myelodysplastic syndrome (MDS), leukemia, a solid tumor, schizophrenia, sickle cell disease, and lupus (SLE).

The invention also provides a method for inhibiting the activity of DNA methyltransferase 1 comprising contacting the DNA methyltransferase 1 with a compound of Formula (I) or a pharmaceutically acceptable salt thereof.

The invention also provides a method for treating a hemaglobinopathy, such as a thalassemia (e.g. beta-thalassemia) in an animal comprising administering a compound of Formula (I) or a pharmaceutically acceptable salt thereof to the animal.

The invention also provides a compound of Formula (I) or a pharmaceutically acceptable salt thereof for use in medical therapy.

The invention also provides the use of a compound of Formula (I) or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for the treatment of cancer in an animal.

The invention also provides the use of a compound of Formula (I) or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for treating a pathological condition or symptom in an animal wherein the activity of DNA methyltransferase 1 is implicated and inhibition of its action is desired.

The invention also provides the use of a compound of Formula (I) or a pharmaceutically acceptable salt thereof for the manufacture of a medicament for the treatment of a hemaglobinopathy, such as a thalassemia (e.g. beta-thalassemia) in an animal.

The invention also provides processes and intermediates disclosed herein that are useful for preparing compounds of Formula (I) or salts thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Illustrates Mean Graph Representations showing the activity profiles of the compound of Example 1 (FIG. 1A) and Halomon (FIG. 1B) in the 60 Tumor Cell Line Screen.

FIG. 2. Shows the in vivo effects of the compound of Example 1 from Test F. Female nude mice with established A549 xenografts (n=7 per group) received injections (i.p.) of the compound of Example 1 or vehicle up to 30 times with no evidence of toxicity. (A) Tumor growth appeared to be reduced in mice treated with the compound of Example 1, but the effect was not statistically significant (p≧0.13). (B) IACUC protocol mandated that mice with ulcerated/necrotic tumors had to be euthanized, but the tumors in mice that had necrosis were substantially smaller than control tumors. The table shows data for the three treated mice euthanized before the end of the experiment due to tumor necrosis. Compare with the mean±SE in the control group.

DETAILED DESCRIPTION

The following definitions are used, unless otherwise described: halo is fluoro, chloro, bromo, or iodo. Alkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, alkylthio, etc., denote both straight and branched groups; but reference to an individual radical such as propyl embraces only the straight chain radical, a branched chain isomer such as isopropyl being specifically referred to. The term cycloalkyl includes monocyclic or polycyclic alkyl rings containing from 3 to 12 carbon atoms. The term alkenyl includes hydrocarbon chains that include one or more (e.g. 1, 2, 3, or 4) double bonds in the chain. The term alkynyl includes hydrocarbon chains that include one or more (e.g. 1, 2, 3, or 4) triple bonds in the chain, and that also may optionally include one or more (e.g. 1, 2, 3, or 4) double bonds in the chain. The number of carbons in a hydrocarbon chain (e.g. alkyl, alkenyl, or alkynyl) may be designated herein, for example, by (C₁-C₂₀), which means a chain comprising from 1 to 20 carbon atoms, or by another similar designation.

Aryl denotes a phenyl radical or an ortho-fused bicyclic carbocyclic radical having about nine to ten ring atoms in which at least one ring is aromatic. Heteroaryl encompasses a radical of a monocyclic aromatic ring containing five or six ring atoms consisting of carbon and one to four heteroatoms each selected from the group consisting of non-peroxide oxygen, sulfur, and N(X) wherein X is absent, or is H, O, (C₁-C₄)alkyl, phenyl or benzyl, as well as a radical of an ortho-fused bicyclic heterocycle of about eight to ten ring atoms derived therefrom, particularly a benz-derivative or one derived by fusing a propylene, trimethylene, or tetramethylene diradical thereto.

The term “heterocyclyl” refers to a saturated, or partially unsaturated monocyclic radical containing 4-7 atoms and at least 1 heteroatom selected from the group consisting of oxygen, sulfur, and nitrogen N(Y), wherein Y is a point of attachment, H, O, (C₁-C₄)alkyl, phenyl or benzyl, as well as a radical of a bicyclic or tricyclic ring system derived therefrom, particularly, one derived by fusing a propylene, trimethylene, or tetramethylene diradical thereto, or one derived by fusing an aryl (e.g. a benz-group) or heteroaryl ring thereto.

As used herein the term “arylcarbonyloxy” means a group of the formula aryl-C(═O)—O—, wherein aryl has the meaning described hereinabove.

As used herein the term “heteroarylcarbonyloxy” means a group of the formula heteroaryl-C(═O)—O—, wherein heteroaryl has the meaning described hereinabove.

As used herein the term “aryloxycarbonyl” means a group of the formula aryl-O—C(═O)—, wherein aryl has the meaning described hereinabove.

As used herein the term “heteroaryloxycarbonyl” means a group of the formula heteroaryl-O—C(═O)—, wherein heteroaryl has the meaning described hereinabove.

It will be appreciated by those skilled in the art that compounds of the invention having a chiral center may exist in and be isolated in optically active and racemic forms. Some compounds may exhibit polymorphism. It is to be understood that the present invention encompasses any racemic, optically-active, polymorphic, or stereoisomeric form, or mixtures thereof, of a compound of the invention, which possess the useful properties described herein, it being well known in the art how to prepare optically active forms (for example, by resolution of the racemic form by recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase) and how to determine anti-cancer activity using the standard tests described herein, or using other similar tests which are well known in the art.

Specific values listed below for radicals, substituents, and ranges are for illustration only; they do not exclude other defined values or other values within defined ranges for the radicals and substituents.

Specifically, (C₁-C₂₀)alkyl can be methyl, ethyl, propyl, isoproproyl, butyl, isobutyl, tertbutyl, pentyl, 3-pentyl, 2,2-dimethylprop-1-yl, hexyl, heptyl, octyl, nonyl, or decyl, etc.; (C₁-C₂₀)alkanoyl can be acetyl, propanoyl or butanoyl, etc.; (C₁-C₂₀)alkoxy can be methoxy, ethoxy, propoxy, isopropoxy, butoxy, pentoxy, or hexyloxy; (C₁-C₂₀)alkylthio can be methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio, pentylthio, or hexylthio; (C₂-C₂₀)alkenyl can be vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl, etc.; (C₂-C₂₀)alkynyl can be ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, or 5-hexynyl, etc.; (C₁-C₂₀)alkanoyl can be acetyl, propanoyl or butanoyl, etc.; (C₁-C₂₀)alkoxycarbonyl can be methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, tertbutoxycarbonyl, pentoxycarbonyl, or hexyloxycarbonyl, etc.; (C₁-C₂₀)alkanoyloxy can be acetoxy, propanoyloxy, butanoyloxy, isobutanoyloxy, tertbutanoyloxy, pentanoyloxy, or hexanoyloxy, etc.; aryl can be phenyl, indenyl, or naphthyl; heterocycle can be morpholinyl, piperazinyl, piperidinyl, pyrrolidinyl, tetrahydropyranyl, tetrahydrofuranyl, 1,4-dioxanyl, tetrahydropyridinyl, thiomorpholinyl, azetidinyl, aziridinyl, dihydroisoindoyl, 1,3-dioxolane or dihydroisoquinolinyl; and heteroaryl can be furyl, imidazolyl, triazolyl, triazinyl, oxazoyl, isoxazoyl, thiazolyl, isothiazoyl, pyrazolyl, pyrrolyl, pyrazinyl, tetrazolyl, pyridyl, (or its N-oxide), thienyl, pyrimidinyl (or its N-oxide), indolyl, isoquinolyl (or its N-oxide) or quinolyl (or its N-oxide).

A specific value for R₁ is carboxy.

A specific value for R₁ is (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxy-carbonyl, or (C₂-C₂₀)alkynyloxycarbonyl.

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, is substituted with one or more groups independently selected from carboxy, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, and (C₂-C₂₀)alkynyloxycarbonyl, and which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, (C₁-C₂₀)alkylthio, (C₂-C₂₀)alkenylthio, (C₂-C₂₀)alkynylthio, aryl, heteroaryl, and NR_(a)R_(b).

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, is substituted with one or more groups independently selected from carboxy, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, and (C₂-C₂₀)alkynyloxycarbonyl.

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, is substituted with one or more carboxy.

A specific value for R₁ is (C₁-C₁₀)alkyl, which (C₁-C₁₀)alkyl is substituted with one or more groups independently selected from carboxy, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, and (C₂-C₂₀)alkynyloxycarbonyl.

A specific value for R₁ is (C₁-C₁₀)alkyl, which (C₁-C₁₀)alkyl is substituted with one or more carboxy.

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, is substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, (C₁-C₂₀)alkylthio, (C₂-C₂₀)alkenylthio, (C₂-C₂₀)alkynylthio, carboxy, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, (C₂-C₂₀)alkynyloxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b).

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl is substituted with hydroxy, mercapto, carboxy or NR_(a)R_(b).

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl is substituted with hydroxy.

A specific value for R₁ is (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl is substituted on the carbon adjacent to the triple bond in Formula (I) with hydroxy.

A specific value for R₁ is a (C₅-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl that is substituted with hydroxy, mercapto, carboxy or NR_(a)R_(b).

A specific value for R₁ is a (C₅-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl that is substituted with hydroxy.

A specific value for R₁ is a (C₅-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl that is substituted on the carbon adjacent to the triple bond in Formula (I) with hydroxy.

A specific value for R₁ is a (C₅-C₁₀)alkyl that is substituted with hydroxy, mercapto, carboxy or NR_(a)R_(b).

A specific value for R₁ is a (C₅-C₁₀)alkyl that is substituted with hydroxy.

A specific value for R₁ is a (C₅-C₁₀)alkyl that is substituted on the carbon adjacent to the triple bond in Formula (I) with hydroxy.

A specific value for R₁ is 2,2-dimethyl1-hydroxyprop-1-yl, 1-hydroxyhept-4-ene-1-yl, 2-ethyl-1-hydroxyhex-1-yl, 3-phenyl-1-hydroxyprop-1-yl, 1-hydroxy-hex-1-yl, R-1-hydroxy-hex-1-yl, S-1-hydroxy-hex-1-yl, carboxy, 1-bromohex-1-yl, 1-benzoyloxyhex-1-yl, 1-acetoxyhex-1-yl, 1-phenoxyhex-1-yl, 1-hydroxy-but-1-yl, 1-hydroxyoct-1-yl, 1-hydroxy-1-dec-1-yl, 1-hydroxy-1-dodec-1-yl, 1-cyclopropyl-1-hydroxymethyl, 1-cyclohexyl-1-hydroxymethyl, 1-hydroxy-2,4-hexadiene-1-yl, 2-ethyl-1-hydroxyhex-1-yl, 2-methyl-1-hydroxypent-1-yl, 3[N-(benzyloxycarbonyl)amino]-1-hydroxyprop-1-yl, or

A specific value for R₁ is 1-hydroxyhex-3-ene-1-yl.

A specific value for R₂ is CF₂Br, CFHBr, CF₂Cl, or CFHCl.

A specific value for R₂ is CF₂Br.

A specific compound of formula (I) is a compound of formula (II):

wherein: R₃ is hydroxy, mercapto, chloro, bromo, methylthio, ethylthio, methoxy, ethoxy, or acetylamino; and R₄ is (C₄-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl, which (C₄-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₁₀)alkoxy, (C₁-C₁₀)alkylthio, carboxy, (C₁-C₁₀)alkoxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b). A specific value for R₄ is (C₄-C₁₀)alkyl that is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₁₀)alkoxy, (C₁-C₁₀)alkylthio, carboxy, (C₁-C₁₀)alkoxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b).

A specific compound of the invention is a compound of formula (I): R₁≡R₂  (I) wherein: R₁ is carboxy, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, (C₂-C₂₀)alkynyloxycarbonyl, (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, which (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, or (C₂-C₂₀)alkynyl, is substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, (C₁-C₂₀)alkylthio, (C₂-C₂₀)alkenylthio, (C₂-C₂₀)alkynylthio, carboxy, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, (C₂-C₂₀)alkynyloxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b);

R₂ is CF₂Br, CFHBr, CF₂Cl, CFHCl, CFBr₂, CFCl₂, CBr₃, C(R_(c))(R_(d))Br, C(R_(c))(R_(d))Cl, CF(R_(e))Br, or CCl₃;

each R_(a) and R_(b) is independently H, (C₁-C₂₀)alkyl, (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl, (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, or (C₂-C₂₀)alkynyloxy;

each R_(c) and R_(d) is independently H, (C₁-C₂₀)alkyl, (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl, (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, or (C₂-C₂₀)alkynyloxy; and

R_(e) is (C₁-C₂₀)alkyl, (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl, (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, or (C₂-C₂₀)alkynyloxy;

wherein each aryl or heteroaryl of R₁ is optionally substituted with one or more groups independently selected from halo, hydroxy, nitro, cyano, trifluoromethyl, trifluoromethoxy, mercapto, carboxy, (C₁-C₂₀)alkyl, (C₂-C₂₀)alkenyl, (C₂-C₂₀)alkynyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, (C₁-C₂₀)alkylthio, (C₂-C₂₀)alkenylthio, (C₂-C₂₀)alkynylthio, (C₁-C₂₀)alkoxycarbonyl, (C₂-C₂₀)alkenyloxycarbonyl, (C₂-C₂₀)alkynyloxycarbonyl, aryl, heteroaryl, aryl(C₁-C₂₀)alkyl, heteroaryl(C₁-C₂₀)alkyl, aryl(C₂-C₂₀)alkenyl, aryl(C₂-C₂₀)alkynyl, heteroaryl(C₂-C₂₀)alkenyl, heteroaryl(C₂-C₂₀)alkynyl, (C₁-C₂₀)alkanoyloxy, (C₂-C₂₀)alkenoyloxy, (C₂-C₂₀)alkynoyloxy;

or a pharmaceutically acceptable salt thereof.

A specific value for R₄ is (C₄-C₁₀)alkyl that is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, carboxy, (C₁-C₁₀)alkoxycarbonyl, and NR_(a)R_(b).

A specific value for R₄ is (C₄-C₁₀)alkyl.

A specific value for R₄ is (C₄-C₆)alkyl.

A specific compound of Formula (I) is 1-bromo-1,1-difluoro-4-hydroxy-2-nonyne or 1-bromo-1,1-difluoro-4-hydroxy-5,5-dimethyl-2-hexyne, or a salt thereof

A specific compound of Formula (I) is

or a salt thereof.

Processes for preparing compounds of Formula (I) or salts thereof are provided as further embodiments of the invention and are illustrated by the following procedures in which the meanings of the generic radicals are as given above unless otherwise qualified.

A compound of Formula (I) can be prepared by reacting a deprotonated terminal alkyne of formula 1 with an electrophile of formula 2 wherein X is a suitable leaving group. The terminal alkyne may include one or more other functional groups or protected functional groups.

As illustrated below, a compound of Formula (I) wherein R₁ is a (C₁-C₂₀)alkyl that is substituted on the carbon adjacent to the triple bond in Formula (I) with hydroxy, and that is optionally further substituted with one or more groups can be prepared by reacting a trialkylsilyl alkyne of formula 3 with an aldehyde of formula 4 to provide the corresponding compound of Formula (I).

The reaction can conveniently be carried out by treating the compound of formula 3 with the aldehyde 4 and a fluoride ion source (e.g., tetrabutylammonium fluoride) in a suitable solvent.

The compound of formula 5 can be further modified to provide other compounds of Formula (I), such as compounds of formula 6-8, as illustrated below.

Conversion of an alcohol of formula 5, for example by bromination with CBr₄ and triphenylphosphine, provides a bromide of formula 6. Treatment of an alcohol of formula 5 with diethyl azodicarboxylate (DEAD), triphenylphosphine, and a thiol of formula RSH provides a sulfide of formula 7. Treatment of an alcohol of formula 5, with diethyl azodicarboxylate, triphenylphosphine, and an amide (e.g., of formula CH₃CONH₂) provides an amide of formula 8.

Compound 9 below was first reported in the literature (Journal of the Chemical Society, Perkin Transactions 1: 1063-5; 1982). As illustrated below, it can also be prepared as described by G. B. Hammond J. Fluorine Chem. 2006, 127, 476-488.

Compounds of Formula (I) wherein R₁ is an alkyl, alkenyl, or alkynyl group that is substituted with a carboxy group can be prepared by reacting the corresponding alkynyl lithium with dibromodifluoromethane.

A compound of Formula (II) wherein R₃ is hydroxy and R₂ is CH₂Br can be prepared as illustrated below.

PG=protecting group such as dihydropyranyl

Intermediates of formulae 1-4 are particularly useful for preparing compounds of Formula (I).

In cases where compounds are sufficiently basic or acidic, a salt of a compound of Formula (I) can be useful as an intermediate for isolating or purifying a compound of Formula (I). Additionally, administration of a compound of Formula (I) as a pharmaceutically acceptable acid or base salt may be appropriate. Examples of pharmaceutically acceptable salts are organic acid addition salts formed with acids which form a physiological acceptable anion, for example, tosylate, methanesulfonate, acetate, citrate, malonate, tartarate, succinate, benzoate, ascorbate, α-ketoglutarate, and α-glycerophosphate. Suitable inorganic salts may also be formed, including hydrochloride, sulfate, nitrate, bicarbonate, and carbonate salts.

Pharmaceutically acceptable salts may be obtained using standard procedures well known in the art, for example by reacting a sufficiently basic compound such as an amine with a suitable acid affording a physiologically acceptable anion. Alkali metal (for example, sodium, potassium or lithium) or alkaline earth metal (for example calcium) salts of carboxylic acids can also be made.

The compounds of Formula (I) can be formulated as pharmaceutical compositions and administered to a mammalian host, such as a human patient, in a variety of forms adapted to the chosen route of administration, e.g., orally or parenterally, by intravenous, intramuscular, topical or subcutaneous routes.

Thus, the present compounds may be systemically administered, e.g., orally, in combination with a pharmaceutically acceptable vehicle such as an inert diluent or an assimilable edible carrier. They may be enclosed in hard or soft shell gelatin capsules, may be compressed into tablets, or may be incorporated directly with the food of the patient's diet. For oral therapeutic administration, the active compound may be combined with one or more excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contain at least 0.1% of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 2 to about 60% of the weight of a given unit dosage form. The amount of active compound in such therapeutically useful compositions is such that an effective dosage level will be obtained.

The tablets, troches, pills, capsules, and the like may also contain the following: binders such as gum tragacanth, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, fructose, lactose or aspartame or a flavoring agent such as peppermint, oil of wintergreen, or cherry flavoring may be added. When the unit dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be present as coatings or to otherwise modify the physical form of the solid unit dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac or sugar and the like. A syrup or elixir may contain the active compound, sucrose or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring such as cherry or orange flavor. Of course, any material used in preparing any unit dosage form should be pharmaceutically acceptable and substantially non-toxic in the amounts employed. In addition, the active compound may be incorporated into sustained-release preparations and devices.

The active compound may also be administered intravenously or intraperitoneally by infusion or injection. Solutions of the active compound or its salts can be prepared in water, optionally mixed with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, triacetin, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.

The pharmaceutical dosage forms suitable for injection or infusion can include sterile aqueous solutions or dispersions or sterile powders comprising the active ingredient which are adapted for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions, optionally encapsulated in liposomes. In all cases, the ultimate dosage form should be sterile, fluid and stable under the conditions of manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid dispersion medium comprising, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the formation of liposomes, by the maintenance of the particle size in the case of dispersions or by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, buffers or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.

Sterile injectable solutions are prepared by incorporating the active compound in the appropriate solvent with various of the other ingredients enumerated above, followed by filter sterilization. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying techniques, which yield a powder of the active ingredient plus any additional desired ingredient present in the previously sterile-filtered solutions.

For topical administration, the present compounds may be applied in pure form, e.g., when they are liquids. However, it will generally be desirable to administer them to the skin as compositions or formulations, in combination with a dermatologically-acceptable carrier, which may be a solid or a liquid.

Useful solid carriers include finely divided solids such as talc, clay, microcrystalline cellulose, silica, alumina and the like. Useful liquid carriers include water, alcohols or glycols or water-alcohol/glycol blends, in which the present compounds can be dissolved or dispersed, optionally with the aid of non-toxic surfactants. Adjuvants such as fragrances and additional antimicrobial agents can be added to optimize the properties for a given use. The resultant liquid compositions can be applied from absorbent pads, used to impregnate bandages and other dressings, or sprayed onto the affected area using pump-type or aerosol sprayers.

Thickeners such as synthetic polymers, fatty acids, fatty acid salts and esters, fatty alcohols, modified celluloses or modified mineral materials can also be employed with liquid carriers to form spreadable pastes, gels, ointments, soaps, and the like, for application directly to the skin of the user.

Examples of useful dermatological compositions which can be used to deliver the compounds of Formula (I) to the skin are known to the art; for example, see Jacquet et al. (U.S. Pat. No. 4,608,392), Geria (U.S. Pat. No. 4,992,478), Smith et al. (U.S. Pat. No. 4,559,157) and Wortzman (U.S. Pat. No. 4,820,508).

Useful dosages of the compounds of Formula (I) can be determined by comparing their in vitro activity, and in vivo activity in animal models. Methods for the extrapolation of effective dosages in mice, and other animals, to humans are known to the art; for example, see U.S. Pat. No. 4,938,949.

Generally, the concentration of the compound(s) of Formula (I) in a liquid composition, such as a lotion, will be from about 0.1-25 wt-%, preferably from about 0.5-10 wt-%. The concentration in a semi-solid or solid composition such as a gel or a powder will be about 0.1-5 wt-%, preferably about 0.5-2.5 wt-%.

The amount of the compound, or an active salt or derivative thereof, effective for use in treatment will vary not only with the particular salt selected but also with the route of administration, the nature of the condition being treated and the age and condition of the patient and will be ultimately at the discretion of the attendant physician or clinician.

In general, however, a suitable dose will be in the range of from about 0.5 to about 100 mg/kg, e.g., from about 10 to about 75 mg/kg of body weight per day, such as 3 to about 50 mg per kilogram body weight of the recipient per day, preferably in the range of 6 to 90 mg/kg/day, most preferably in the range of 15 to 60 mg/kg/day.

The compound can be conveniently administered in unit dosage form; for example, containing 5 to 1000 mg, conveniently 10 to 750 mg, most conveniently, 50 to 500 mg of active ingredient per unit dosage form.

Ideally, the active ingredient should be administered to achieve peak plasma concentrations of the active compound of from about 0.5 to about 75 μM, preferably, about 1 to 50 μM, most preferably, about 2 to about 30 μM. This may be achieved, for example, by the intravenous injection of a 0.05 to 5% solution of the active ingredient, optionally in saline, or orally administered as a bolus containing about 1-100 mg of the active ingredient. Desirable blood levels may be maintained by continuous infusion to provide about 0.01-5.0 mg/kg/hr or by intermittent infusions containing about 0.4-15 mg/kg of the active ingredient(s).

The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations; such as multiple inhalations from an insufflator or by application of a plurality of drops into the eye.

Compounds of the invention can also be administered in combination with other therapeutic agents, for example, other agents that are useful for the treatment of cancer. Examples of such agents include alkylating agents (e.g. carmustine, chlorambucil, cisplatin, lomustine, cyclophosphamide, melphalan, mechlorethamine, procarbazine, thiotepa, uracil mustard, triethylenemelamine, busulfan, pipobroman, streptozocin, ifosfamide, dacarbazine, carboplatin, and hexamethylmelamine), antimetabolites (e.g. cytosine arabinoside, fluorouracil, gemcitabine, hydroxyurea, mercaptopurine, methotrexate, azaserine, thioguanine, floxuridine, fludarabine, cladribine and L-asparaginase), natural products (e.g. actinomycin D, bleomycin, camptothecins, daunomycin, doxorubicin, etoposide, mitomycin C, (paclitaxel), taxotere, teniposide, vincristine, vinorelbine, mithramycin, idarubicin, (plicamycin), and deoxycoformycin), hormonal agents (e.g. tamoxifen), and other agents (e.g. mitotane, mitoxantrone, vinblastine, and levamisole).

In a specific embodiment of the invention, the compound can be administered or formulated in combination with one or more other DNMT inhibitors (e.g. dacitabine).

In a specific embodiment of the invention, the compound can be administered or formulated in combination with one or more HDAC inhibitors (e.g. vorinostat).

In a specific embodiment of the invention, the compound can be administered or formulated in combination with one or more other therapeutic agents (e.g. sorafenib, sutent, herceptin, avastatin, gleevec, iressa, or tarceva).

Accordingly, in one embodiment the invention also provides a composition comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof, at least one other therapeutic agent, and a pharmaceutically acceptable diluent or carrier. The invention also provides a kit comprising a compound of Formula (I), or a pharmaceutically acceptable salt thereof, at least one other therapeutic agent, packaging material, and instructions for administering the compound of Formula (I) or the pharmaceutically acceptable salt thereof and the other therapeutic agent or agents to an animal to treat a condition (e.g. cancer).

The ability of a compound of the invention to act as an anticancer agent may be determined using pharmacological models which are well known to the art, or using Test A described below.

Test A.

A test compound is suspended in sterile water or DMSO and diluted with sterile water to appropriate concentrations (final DMSO will be <0.5%). Samples are added to MDA-MB-231 and MCF7 breast cancer cells plated in 96 well plates to give final concentrations of 10⁻¹⁰, 10⁻⁹, 10⁻⁸, 10⁻⁷, 10⁻⁶ M in triplicate wells. Each plate contains a positive control and a negative control (untreated cells). Cells are incubated for 4 days and proliferation is measured using the colorimetric MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay (see Morgan, “Tetrazolium (MTT) Assay for Cellular Viability and Activity” Methods in Molecular Biology (1998) Vol. 79, pp. 179-183). Representative compounds of Formula (I) were tested in this assay and were found to have useful activity.

The ability of a compound of the invention to act as an inhibitor of DNMT1 may be determined using pharmacological models which are well known to the art, or using Test B described below.

Test B In Vitro Enzyme Assay Using Recombinant Human DNMT1

A method similar to that described by Lee et al. 2006 (Lee et al., “Inhibition of DNA methylation by caffeic acid and chlorogenic acid, two common catechol-containing coffee polyphenols” Carcinogenesis (Feb. 2006) Vol. 27, No. 2, pp. 269-277) can be used to evaluate the ability of a compound to act as an inhibitor of DNMT1. Briefly, compounds are incubated with recombinant human DNMT1 (which is commercially available), hemimethylated DNA substrate (poly[dI-dC]) and S-adenosyl-[methyl-³H]-methionine as a methyl donor. After the reaction, DNA is precipitated and incorporated ³H is measured. Caffeic acid at 20 μM is used as a positive control.

The ability of a compound of the invention to affect DNA methylation in cultured cells may be determined using pharmacological models which are well known to the art, or using Test C described below.

Test C Effects on Promoter Methylation and Gene Expression in Breast Cancer Cells

Genes that are known to be regulated by promoter methylation in breast cancer cells, including estrogen receptor RASS1FA and CDKN2A are evaluated. RT-PCR and western blotting analyses is carried out for these gene products using extracts from MCF7 and MDA-MB-231 breast cancer cells that have been treated with varying doses of a compound of Formula (I). Expression is examined at several time points and 5-azacytidine is used as a positive control. Methylation specific PCR is used to confirm that activity is due to demethylation of the relevant promoter. Briefly, genomic DNA is treated with sodium bisulfate, which converts unmethylated cytosines to uracil. Complementary PCR primers will therefore require A to recognize uracil (from unmethylated cytosines), but G to recognize methylated cytosines. A nested PCR protocol can thus distinguish between methylated and unmethylated promoters.

Test D Anti-Cancer Activity

The compound of Example 1 below was screened against a panel of 60 human tumor cell lines. This screening revealed that the compound was potent and that the compound had a distinctive pattern of activity. The compound was highly active in breast, prostate, colon and brain (CNS) tumor cells, but less potent in other tumor types, e.g. melanomas. One of the most sensitive cell types was breast cancer, with all seven of the cell lines (including a doxorubicin-resistant line) having GI₅₀ values in the 10-66 nM range.

Analysis of the 60 cell line data using the on-line COMPARE program, which allows comparison of the activity profile of a “seed” with the more than 60,000 compounds in the public database, was also carried out. When the compound of Example 1 was used as a COMPARE seed, a strong correlation (Pearson coefficient 0.82) with a compound known as halomon was found. Halomon is a halogenated monoterpene that is structurally distinct from the compound of Example 1. Nonetheless, similarity for certain tumor types (e.g. breast, colon, CNS) and for specific cell lines within each panel was found. These results suggest that the compound of Example 1 and halomon share the same mechanism of action. Mean Graph Representations showing the activity profiles of the compound of Example 1 and Halomon (right panel) in the 60 Tumor Cell Line Screen are shown in FIG. 1.

Test E The Methyltransferase Activity of the Compound of Example 1 was Evaluated as Follows.

For experiments 1 and 2, A549 non-small cell lung cancer cells were incubated with the compound of Example 1 (1 μM final concentration) or vehicle (untreated) for 2 h and nuclear extracts were prepared by standard methods. The total DNA methyltransferase activity of the extracts was measured using EpiQuik™ DNA Methyltransferase Activity/Inhibition Assay Kit (Epigentek, Brooklyn, N.Y.), according to the manufacturer's directions. For experiment 3, the assay was carried out using purified HeLa nuclear extracts in the presence of the compound of Example 1 (500 nM final concentration) or vehicle (untreated).

The assay involves incubation of nuclear extracts (as a source of DNA methyltransferase activity) with immobilized DNA substrate in the presence of Adomet (methyl donor). The DNA methyltransferase activity was measured by determining levels of 5-methylcytosine in the DNA substrate using a primary antibody to 5-methylcytosine and a secondary antibody for colorimetric detection at 450 nm. Results are presented in the following table.

TABLE Relative DNA Methyltransferase Activity 2. Repeat exper- 1. Using nuclear iment using nu- 3. Using 20 extracts clear extracts μg of HeLa nu- from untreated or from untreated or clear extracts Example 1 treated Example 1 treated incubated in (1 μM for 2 h) (1 μM for 2 h) vitro with 500 Experiment lung cancer cells. lung cancer cells. nM Example 1 Untreated 0.114 0.122 0.264 Example 0.073 0.075 0.092 1-treated Test F In-vivo Effects of Compound of Example 1.

The following study was designed to assess toxicity and activity in female nude mice bearing A549 human non-small cell lung cancer xenografts. Athymic nude mice were inoculated subcutaneously (s.c.) with A549 cells and treatment began after small tumors were visible. The compound of Example 1 was prepared at 100 mg/ml or 50 mg/ml in DMSO and diluted 1:10 with sterile PBS. Mice were treated by intraperitoneal (i.p.) injections of 100 μl of these solutions, equivalent to approximately 25 mg/kg or 50 mg/kg; the control group received identical injections of vehicle (10% DMSO in PBS). Mice received injections of the compound of Example 1 or vehicle five times per week (once per day, except on weekends) for up to 30 injections. There was no evidence of acute toxicity in mice treated with the compound of Example 1, as judged by body weight and behavior of the mice The tumors grew slower in the treated mice compared to control-treated mice, although the difference was not statistically significant (see A in FIG. 2). Evaluating the long-term outcome was complicated by the fact that several animals in the compound of Example 1 treated groups developed tumor necrosis/ulceration and had to be euthanized before the end of the experiment, as required by IACUC protocol. This tumor necrosis is believed to be treatment-related as it occurred in 5/12 treated animals, but 0/6 of the control group. There was suggestion that the observed tumor necrosis was predictive of an anti-tumor effect, because the size of the ulcerated tumors was substantially smaller than those in the control group at the same time point (see B in FIG. 2). The overall response seemed to be equivalent or better in the low dose group compared with the high dose group, but that may be consistent with the mechanism of action, since a similar effect has been observed for decitabine in humans. These in vivo results show that the compound of Example 1 exhibits no evidence of acute toxicity and suggesting it can induce tumor necrosis in a mouse model of cancer.

The invention will now be illustrated by the following non-limiting Examples.

Example 1 Synthesis of 1-bromo-1,1-difluoro-non-2-yn-4-ol

To a solution of (3-bromo-3,3-difluoro-prop-1-ynyl)-triisopropyl-silane (156 mg, 0.5 mmol) and hexanal (60 mg, 0.6 mmol) in THF (5 mL), TBAF (1M, 0.75 mL) was added dropwise at −90° C. After the addition was completed, the reaction mixture was stirred for 0.5 h and quenched with saturated aq. NH₄Cl. The mixture was extracted with ether (20 mL×3) and washed with water (20 mL×2). After drying over Na₂SO₄ the solvent was removed and the product was purified by silica gel chromatography (AcOEt:hexane=1:20) to afford the title compound (82 mg, 65%) as colorless liquid. Colorless liquid, yield: 78%. IR (neat): 3320, 2934, 2261, 1223, 1096 cm−1. 1H NMR (500 MHz, CDCl3) δ 4.49-4.52 (m, 1H), 2.14 (bs, 1H), 1.74-1.77 (m, 2H), 1.45-1.47 (m, 2H), 1.33-1.38 (m, 4H), 0.91 (t, J=6.5 Hz, 3H); 19F NMR (470 MHz, CDCl3) δ −32.9 (s, 2F); 13C NMR (125 MHz, CDCl3) δ 101.5 (t, J=288 Hz), 91.5 (t, J=5.8 Hz), 77.3 (t, J=38 Hz), 62.2, 36.8, 31.4, 24.6, 22.6, 14.1; GCMS: 157, 137, 115, 104, 91.

Example 2 Synthesis of S-1-Bromo-1,1-difluoro-non-2-yn-4-ol

To a solution of 2-[1-(3-Bromo-3,3-difluoro-prop-1-ynyl)-hexyloxy]-tetrahydro-pyran (1.08 g, 3.2 mmol) 20 mL methanol, TsOH.H₂O (12 mg, 0.069 mmol) was added. After the addition was completed, the reaction mixture was stirred for 12 h and quenched with saturated aq. NaHCO₃. The mixture was extracted with ether (20 mL×3) and washed with water (20 mL×2). After drying over Na₂SO₄ the solvent was removed and the product was purified by silica gel chromatography (DCM:Hexane=1:1) to afford the title compound (0.58 g, 71%) as colorless liquid: yield: 78%. IR (neat): 3320, 2934, 2261, 1223, 1096 cm⁻¹. ¹H NMR (500 MHz, CDCl₃) δ 4.49-4.52 (m, 1H), 2.14 (bs, 1H), 1.74-1.77 (m, 2H), 1.45-1.47 (m, 2H), 1.33-1.38 (m, 4H), 0.91 (t, J=6.5 Hz, 3H); ¹⁹F NMR (470 MHz, CDCl₃) δ −32.9 (s, 2F); ¹³C NMR (125 MHz, CDCl₃) δ 101.5 (t, J=288 Hz), 91.5 (t, J=5.8 Hz), 77.3 (t, J=38 Hz), 62.2, 36.8, 31.4, 24.6, 22.6, 14.1; GCMS: 157, 137, 115, 104, 91.

The intermediate 2-[1-(3-Bromo-3,3-difluoro-prop-1-ynyl)-hexyloxy]-tetrahydro-pyran was prepared as follows.

-   a. S-2-(1-Ethynyl-hexyloxy)-tetrahydropyran. To a solution of     S-oct-1-yn-3-ol (900 mg, 7.13 mmol) and 3,4-dihydro-2H-pyran (901     mg, 10.7 mMol) in 5 mL dichloromethane, TsOH.H₂O (13 mg, 0.071 mMol)     was added. After the addition was completed, the reaction mixture     was stirred for 12 h and quenched with saturated aq. NaHCO₃. The     mixture was extracted with DCM (20 mL×3) and washed with water (20     mL×2). After drying over Na₂SO₄ the solvent was removed and the     product was purified by silica gel chromatography     (AcOEt:hexane=1:10) to afford 2-(1-ethynyl-hexyloxy)tetrahydropyran     (1.27 g, 85%) as colorless liquid.     The product was a mixture of two diastereomers (ratio 1:5.8). Major     diastereomer: ¹H NMR (500 MHz, CDCl₃) δ 4.98-4.97 (m, 1H), 4.40-4.43     (m, 1H), 3.79-3.83 (m, 1H), 3.53-3.55 (m, 1H), 2.38 (s, 1H),     1.71-1.84 (m, 4H), 1.44-1.62 (m, 6H), 1.33-1.34 (m, 4H), 0.91 (t,     J=6.5 Hz, 3H) -   b.     2-[1-(3-Bromo-3,3-difluoro-prop-1-ynyl)-hexyloxy]-tetrahydro-pyran.     To a solution of S-2-(1-ethynyl-hexyloxy)tetrahydropyran (1.24 g,     5.9 mmol) in dry THF 30 mL, a 2.5 M hexane solution of     n-butyllithium (2.36 mL, 5.9 mmol) was added dropwise at     approximately −90° C. (liquid N₂/EtOH bath) under an argon     atmosphere. After the reaction mixture was stirred for 30 minutes at     that temperature, the reaction mixture was cooled to −110° C.     (because the solvent along the wall of reaction flask froze at −110°     C., it is helpful to maintain good stirring throughout). Cold     dibromodifluoromethane (5.5 mL, 60 mmol) was added to the mixture by     cannulation. The temperature of the reaction mixture was controlled     very carefully during the addition of CF₂Br₂ using a thermometer     immersed in the reaction mixture. The reaction temperature may rise     to −90° C. or even higher even if CF₂Br₂ is introduced slowly. After     the addition was completed, the mixture was allowed to warm to     −50° C. with stirring during the course of 1 hour and quenched with     sat. aq. NH₄Cl (50 mL). The aqueous layer was extracted with ether     (50 mL) and the organic layer was washed by water (10 mL×3). The     organic layer was dried over Na₂SO₄. After evaporation of the     solvent, the product was purified by silica gel chromatography     (AcOEt:Hexane=1:10) to afford product (1.5 g, 75%) as colorless     liquid. The product is mixture of two diastereomers (ratio 1:9.5).     Major diastereomer: ¹H NMR (500 MHz, CDCl₃) δ 4.88-4.85 (m, 1H),     4.56-4.58 (m, 1H), 3.78-3.81 (m, 1H), 3.55-3.57 (m, 1H), 1.72-1.83     (m, 6H), 1.49-1.64 (m, 4H), 1.33-1.34 (m, 4H), 0.91 (t, J=6.5 Hz,     3H); ¹⁹F NMR (470 MHz, CDCl₃) δ −32.9 (s), −32.3 (d, J=9.8 Hz)

Example 3 Synthesis of 6-Bromo-6,6-difluoro-2,2-dimethyl-hex-4-yn-3-ol

To a solution of (3-bromo-3,3-difluoro-prop-1-ynyl)-triisopropyl-silane (156 mg, 0.5 mmol) and 2,2-dimethyl-propionaldehyde (52 mg, 0.6 mmol) in THF (5 mL), TBAF (1M, 0.75 mL) was added dropwise at −90° C. After the addition was completed, the reaction mixture was stirred for 0.5 hour and quenched saturated aq. NH₄Cl. The mixture was extracted with ether (20 mL×3) and washed with water (20 mL×2). After drying over Na₂SO₄ the solvent was removed and the product was purified by silica gel chromatography (AcOEt:hexane=1:20) to afford the title compound as a colorless liquid. ¹H NMR (500 MHz, CDCl₃) δ 4.08-4.09 (m, 1H), 1.83 (d, J=6.0 Hz, 1H), 0.965 (s, 9H).

Example 4 Synthesis of Representative Compounds of Formula (I)

Using the synthetic processes illustrated above, the following compounds of Formula (I) were prepared. Most compounds were prepared by reaction of TIPS or other silyl protecting group (R′, R″, R′″ methyl, ethyl, phenyl, iso-propyl, tert-butyl, phenyl) substituted difluoropropargyl bromide with an aldehyde in the presence of fluoride ion (TBAF or a suitable source of fluoride ion). Other compounds were made by direct difluorobromomethylation of functionalized terminal alkynes.

Chem- Chem- ical ical shift shift of ¹H of ¹⁹F R₁ R₂ (RCHOH) NMR 2,2-dimethyl-1- bromodifluoromethyl 4.08 −32.8 hydroxyprop-1-yl 1-hydroxyhept-4-ene- bromodifluoromethyl 4.54 −33.0 1-yl 3-phenyl-1-hydroxy- bromodifluoromethyl 5.14 −32.7 prop-1-yl 1-hydroxy-hex-1-yl bromomethyl 3.95 — 1-hydroxy-hex-1-yl bromodifluoromethyl 4.49 −32.9 R-1-hydroxy-hex-1-yl bromodifluoromethyl 4.49 −32.9 S-1-hydroxy-hex-1-yl bromodifluoromethyl 4.49 −32.9 carboxy bromodifluoromethyl — −38.2 1-bromohex-1-yl bromodifluoromethyl 4.52 −33.5 1-benzoyloxyhex-1-yl bromodifluoromethyl 5.75 1-acetoxyhex-1-yl bromodifluoromethyl 5.46 −33.5 1-phenoxyhex-1-yl bromodifluoromethyl 1-hydroxy-but-1-yl bromodifluoromethyl 4.53 −32.8 1-hydroxyoct-1-yl bromodifluoromethyl 4.52 −32.9 1-hydroxy-1-dec-1-yl bromodifluoromethyl 4.52 −32.9 1-hydroxy-1-dodec-1-yl bromodifluoromethyl 4.52 −32.8 1-cyclopropyl-1-hydroxy- bromodifluoromethyl 4.27 −33.0 methyl 1-cyclohexyl-1-hydroxy- bromodifluoromethyl 4.31 −32.7 methyl 1-hydroxy-2,4-hexadiene- bromodifluoromethyl 5.04 −33.3 1-yl 2-ethyl-1-hydroxyhex- bromodifluoromethyl 4.54 −32.8 1-yl 2-methyl-1-hydroxypent- bromodifluoromethyl 4.40 −32.8 1-yl 3-[N-(benzyloxycarbonyl) bromodifluoromethyl 4.61 −33.0 amino]-1-hydroxyprop-1-yl

bromodifluoromethyl 4.48 4.56 −33.8 −33.7

Example 5

The following illustrate representative pharmaceutical dosage forms, containing a compound of Formula (I) (‘Compound X’), for therapeutic or prophylactic use in humans.

(i) Tablet 1 mg/tablet Compound X = 100.0 Lactose 77.5 Povidone 15.0 Croscarmellose sodium 12.0 Microcrystalline cellulose 92.5 Magnesium stearate 3.0 300.0

(ii) Tablet 2 mg/tablet Compound X = 20.0 Microcrystalline cellulose 410.0 Starch 50.0 Sodium starch glycolate 15.0 Magnesium stearate 5.0 500.0

(iii) Capsule mg/capsule Compound X = 10.0 Colloidal silicon dioxide 1.5 Lactose 465.5 Pregelatinized starch 120.0 Magnesium stearate 3.0 600.0

(iv) Injection 1 (1 mg/ml) mg/ml Compound X = (free acid form) 1.0 Dibasic sodium phosphate 12.0 Monobasic sodium phosphate 0.7 Sodium chloride 4.5 1.0N Sodium hydroxide solution q.s. (pH adjustment to 7.0-7.5) Water for injection q.s. ad 1 mL

(v) Injection 2 (10 mg/ml) mg/ml Compound X = (free acid form) 10.0 Monobasic sodium phosphate 0.3 Dibasic sodium phosphate 1.1 Polyethylene glycol 400 200.0 0.1N Sodium hydroxide solution q.s. (pH adjustment to 7.0-7.5) Water for injection q.s. ad 1 mL

(vi) Aerosol mg/can Compound X = 20.0 Oleic acid 10.0 Trichloromonofluoromethane 5,000.0 Dichlorodifluoromethane 10,000.0 Dichlorotetrafluoroethane 5,000.0 The above formulations may be obtained by conventional procedures well known in the pharmaceutical art.

All publications, patents, and patent documents are incorporated by reference herein, as though individually incorporated by reference. The invention has been described with reference to various specific and preferred embodiments and techniques. However, it should be understood that many variations and modifications may be made while remaining within the spirit and scope of the invention. 

What is claimed is:
 1. A method for treating cancer in an animal comprising administering to the animal a compound of Formula (II):

wherein: R₃ is hydroxy, mercapto, chloro, bromo, methylthio, ethylthio, methoxy, ethoxy, acetylamino, (C₁-C₂₀)alkanoyloxy, arylcarbonyloxy, or aryloxy; and R₄ is (C₄-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl, which (C₄-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₁₀)alkoxy, (C₁-C₁₀)alkylthio, carboxy, (C₁-C₁₀)alkoxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b); each R_(a)and R_(b) is independently H, (C₁-C₂₀)alkyl, (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl, (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, or aryl-(C₁-C₂₀)alkoxycarbonyl; or a pharmaceutically acceptable salt thereof, wherein the cancer is breast cancer, prostate cancer, colon cancer, brain cancer, or non-small cell lung cancer.
 2. The method of claim 1 wherein the cancer is a solid tumor.
 3. The method of claim 1 wherein the cancer is breast cancer, colon cancer, or brain cancer.
 4. The method of claim 1 wherein the animal is a human.
 5. A method for inhibiting methyltransferase activity, wherein the method comprises administering an effective amount of a compound of Formula (II):

wherein: R₃ is hydroxy, mercapto, chloro, bromo, methylthio, ethylthio, methoxy, ethoxy, acetylamino, (C₁-C₂₀)alkanoyloxy, arylcarbonyloxy, or aryloxy; and R₄ is (C₄-C₁₀)alkyl, or (C₂-C₁₀)alkynyl, which (C₄-C₁₀)alkyl, (C₂-C₁₀)alkenyl, or (C₂-C₁₀)alkynyl is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₁₀)alkoxy, (C₁-C₁₀)alkylthio, carboxy, (C₁-C₁₀)alkoxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b); each R_(a) and R_(b) is independently H, (C₁-C₂₀)alkyl, (C₁-C₂₀)alkanoyl, (C₂-C₂₀)alkenylcarbonyl, (C₂-C₂₀)alkynylcarbonyl, (C₁-C₂₀)alkoxy, (C₂-C₂₀)alkenyloxy, (C₂-C₂₀)alkynyloxy, or aryl-(C₁-C₂₀)alkoxycarbonyl; or a pharmaceutically acceptable salt thereof.
 6. The method of claim 5, wherein the methyltransferase is a DNA methyltransferase.
 7. The method of claim 6, wherein the DNA methyltransferase is DNA methyltransferase
 1. 8. The method of claim 5, wherein the compound of Formula (II) is administered to a cell or cells.
 9. The method of claim 5, wherein the compound of Formula (II) is administered to an individual.
 10. The method of claim 9, wherein the individual has cancer and the cancer is breast cancer, prostate cancer, colon cancer, brain cancer, or non-small cell lung cancer.
 11. The method of claim 10, wherein the cancer is a solid tumor.
 12. The method of claim 5, wherein R₄ is (C₄-C₁₀)alkyl or (C₂-C₁₀)alkenyl, which (C₄-C₁₀)alkyl or (C₂-C₁₀)alkenyl is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₁₀)alkoxy, (C₁-C₁₀)alkylthio, carboxy, (C₁-C₁₀)alkoxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b).
 13. The method of claim 5, wherein the compound of Formula (II) is 1-bromo-1,1-difluoro-4-hydroxy-5,5-dimethyl-2-hexyne.
 14. The method of claim 5, wherein the compound of Formula (II) is a compound having the formula:


15. The method of claim 1, wherein the cancer is colon cancer or breast cancer.
 16. The method of claim 1, wherein the cancer is non-small cell lung cancer.
 17. The method of claim 1, wherein R₄ is (C₄-C₁₀)alkyl or (C₂-C₁₀)alkenyl, which (C₄-C₁₀)alkyl or (C₂-C₁₀)alkenyl is optionally substituted with one or more groups independently selected from halo, hydroxy, mercapto, (C₁-C₁₀)alkoxy, (C₁-C₁₀)alkylthio, carboxy, (C₁-C₁₀)alkoxycarbonyl, aryl, heteroaryl, and NR_(a)R_(b).
 18. The method of claim 1, wherein the compound of Formula (II) is 1-bromo-1,1-difluoro-4-hydroxy-5,5-dimethyl-2-hexyne.
 19. The method of claim 1, wherein the compound of Formula (II) is a compound having the formula: 